Abstract Details
| Name: ARITRA CHAKRABARTY Affiliation: JRF Conference ID: ASI2018_1316 Title : Limb Darkening of Brown Dwarfs Authors and Co-Authors : Aritra Chakrabarty, Indian Institute of Astrophysics and Sujan Sengupta, Indian Institute of Astrophysics Abstract Type : Poster Abstract Category : Stars,ISM and the Galaxy Abstract : Apart from interpreting the light curves of eclipsing binary star systems, estimating stellar diameter and stellar rotation rate, limb darkening laws for main sequence stars play crucial role to determine the physical properties of exoplanets and exoplanetary system. The transit light curves of stars hosting planets require the stellar limb darkening law for accurate analysis. While limb darkening laws for main sequence stars with spectral class ranging from O to K are extensively discussed and determined, the same for low mass stars, e.g., M-dwarfs and sub-stellar mass objects such as Brown Dwarfs have not yet been considered. Discovery of a few exoplanets around Brown Dwarfs through Radial velocity methods and gravitational microlensing method clearly implies that Brown Dwarfs should also have planets, albeit of small, rocky type. Therefore, analysis of transit light curve of Brown Dwarfs with planets require appropriate limb darkening laws in order to interpret the planetary properties. In the present work, we, for the first time present limb darkening laws for cloud-less brown dwarfs by fitting the angle dependent intensities derived by solving multi-scattering radiative transfer equations self-consistently. We use the cloudless radiative-convective equilibrium atmosphere model of Ackerman-Marley that reproduces well the observed flux of T-dwarfs with a wide range of effective temperature and surface gravity. A sixteen Gaussian point grid is adopted to calculate the angle-dependent intensity of the radiation for a wide range of wavelengths and a three parameter fitting is presented as the laws of limb darkening for each effective temperature and for different wave-bands ranging from V- to K-band. The surface gravity of the objects is fixed at 1000 m/s2 . |